Saturday, January 20, 2007

White-tailed Spiders, Lampona species.

A spider with a bad reputation?!

This spider has been accused of biting people and causing flesh-eating ulcers that refuse to heal. However, recent research of 130 bite victims (by two of the most common species from this genus), found no incident of skin damage other than from a painful bite (greater than a bee sting) lasting up to 24 hours. The conclusion given was these spiders are innocent of their reputation.

Nevertheless, something has caused these flesh-eating ulcers, which the people affected claim were from a spider bite. Another possible explanation is the bacteria living around the mouthparts of most spiders, probably as a result of their meals. If this was the cause, it could involve a range of possible spiders as few people have more than an elementary knowledge of spider identification.

Yet another factor, assuming the people were actually bitten by a Lampona species, is there are around 60 recognised species in this genus (occurring Australia wide), but only two of these were tested. Although not all of these spiders have a white spot on their tail, they are however of similar shape and the white dot in most instances is not particularly obvious.

This is one of the White-tailed Spiders. Note the white spot on the tail.

White-tailed Spider a Lampona species

These spiders are wandering night-time hunters that do not build a web, although they sometimes construct a tubular silken retreat, or to lay eggs. Their main diet is other spiders, especially the black house spider, so for those who dislike the look of the house spider and its untidy web, they might prefer the smarter white-tailed spider.

Being hunting spiders their eyesight is good. They have eight eyes (all forward facing) in two rows of four.

During the day, the white-tailed spider rests under bark, logs, rocks or leaf-litter.

This young spider is checking out what the Pie-dish Beetle is eating, but fortunately for the beetle, it is not on the menu.

Most of these spiders are between 1 and 1½ cm in length (excluding legs), but some (like the one below) are closer to 2 cm. I discovered this individual in the open on one of my nightly rambles and like most invertebrates in this situation, they tend to either freeze or move slowly. This one decided to move slowly. It was obviously not happy being caught in the open and initially hugged the ground.

However, it started to become annoyed when I continued to follow it.

In this shot it was very upset and began arching its back, presumably an aggressive posture.

When it reached the weeping foliage of a sedge, it turned and stood on tip-toe like a defensive/aggressive cat, side-on with arched back to make it look more dangerous. It certainly worked on me, as I had no intention of placing a part of my anatomy anywhere near it.

So my advice with spiders, is to treat them all with respect. Don't tease or mess with them because like most wild animals, they will regard you as a threat and are then more likely to bite. If you want to relocate any, simply place a glass over them, then slide a piece of paper or thin board under to trap it. Then release it outside! Alternatively if difficult to reach, a gentle nudge with a broom will usually make the spider crawl aboard so it too can be carried outside, but do it slowly/gently in order not to panic the spider.

Many people are paranoid about spiders, but this is usually due to ignorance and fear. The more you get to know them, the less fearful you become. So get to know your local species and discover how diverse they are in appearance and habit. Most spiders are not aggressive and none are interested in going out of their way to attack you, so inspect them from a respectful distance and learn to appreciate the importance of these creatures in your environment.

17 comments:

I now have live feeds in my FireFox browser and have a feed for your blog and several others, makes it easy to find posts or see if there is any new content. I see that you must have only just posted White-tails.

Thought that there must be more than one species as I've seen different sizes and markings, but I didn't realise that there were 60 odd spp. Do they have representatives in all states?

I was aware that consensus of opinion was that they don't cause the damage once attributed to their bite. A bit of a coincidence that I was only reading about this very subject a week or so ago (if memory serves me right, I think it may have been in "The Lab" somewhere, but I may be mistaken).

Anyway Jack, nice pics and informative text once again.(Have to get a digital camera so I can post images on my blog and make it a bit more appealing to the eye).

Hi Huntervalley, thanks for your comments. I would like to stress that only two species of white-tailed spiders have been cleared of causing ulceration, and the bacterial contamination has not been fully investigated. So all spiders should be treated with caution and respect.

It has been suggested that an introduced spider is responsible for the ulceration, as these spiders are known to cause this aliment overseas. However there is no evidence that these spiders are widespread in Australia or that they have caused past known ulcerations here. But it is another theory that needs investigation.

I am also in the boat of those who kill white-tips. I feel bad whenever I kill a spider, except for white-tips. I have a special fondness for orb weavers.

My brother and mother both got ulcers, and extremely sick, when we first moved into an old house (mentioned previously). The docters had no idea what it was for a long time, but eventually came to conclusion of white-tips. They were extremely numerous in the house, until it was sprayed.

The total count was >10 ulcers on each of them. Since I nor my other brother got any bites, I think it is more re-occurence rather than a bite for every ulcer. I believe this has been reported somewhere before.

Other than that, I would rather have the little black spiders which kill flies than white-tips which kill spiders.

Hi Evan, good to hear from you again. Having a 110 year house is I guess, bound to have a number of uninvited guests.

Re the white-tailed spiders, there is no scientific evidence that they are dangerous to people, but it is wise to be cautious concerning them and all spiders, as even a bite from a harmless species is not a pleasant experience.

It sure is a nice part of the country, if you don't include the coal mine. Check out my photos to see some of the stuff that I have found down there (haven't nearly uploaded everything, but they are some of my favourites)

http://www.flickr.com/photos/52507572@N00/

Yeah, I am doing science. I want to get into frog conservation research. There is a frog lab at the uni which I volunteer for, and I want to do my post grad work there.

If it is a bite which is causing the illness, then there should be some sort of infection on his skin. It will be swollen and pussy, and depending on the stage, will be rotting in the centre.

He needs to go to a doctor straight away. If you are lucky, you will get one who can diagnose the problem. If you suspect white-tip bite, tell the doctor, as they can look it up if they aren't aware of it straight away.

It will probably need to be cut out if it is one, as the rotting continues (this is what happened 10 years ago, treatment may have changed). I have seen terrible photos of this, so don't leave it, get doctor's help straight away.

In a very recent interview (1 week or 2 ago) on the local (Sydney) ABC radio 702, called "the conversation hour", Kev Karmody, the famous indigenous (sp) poet/singer/songwriter ("from little things big things grow") was talking about healthproblems he has had and that he contiued to have thanks to some unkind close encounters with white tail spiders in the past.

I got the impressin from him, that the repercussions on one's health after such a spider bite are ongoing for a long time.

Hi Nina, I hope your father is ok. I would just like to say that trying to carry on a three way conversation via a blog site is probably not the best way to go. May I suggest that you create an anonymous email address with say 'hotmail' and post it here then whoever is interested can contact you direct.

The problem going via the blog is I also have to be available to receive your posts and this could lead to extensive delays.

Hi there. Just today I found one of these spiders on my bed. My partner had just picked up some clothes off the floor to sort for washing, placed them on the bed and then sat sorting them. I luckily saw the spider before it got too close to my fiance, who to be fair would of freaked out, probally agitating it enough for it to become aggressive. So i used the tried and tested method of the glass and card, removed it to a more observable location and was wholly surprised to see it climb the inside of the glass. i can only surmise there must of been a transparent film on the glass from the dishwasher.

im afraid i killed the spider as weve been told not to risk it when it comes to any spider with white on its rear.

This is actually the first picture ive found of one identicle to the one we had in the house (or as identicle as the untrained eye can tell), good to have confirmation of what it was.

Hi DanGlad the blog was of some help to you. White-tailed Spiders are notorious for getting onto peoples beds and on cloths left on the ground. They are excellent climbers and a smooth vertical glass would be no problem for them. These spiders can be quite common in some areas, so keep an eye open for them, although as they don't build a web they are not easy to find. Still don't worry about them, they are not that dangerous and the non-healing bites attributed to them, may be related more to bacteria infection, which could apply to any number of different spider species. However such infections are extremely rare, so you would be very unlucky to become a victim.With best wishesJack

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